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Watch: Nobel Prize-winning efforts show stars orbiting the black hole at the center of our galaxy

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Scientists can’t see the supermassive black hole, called Sagittarius A*, at the center of our Milky Way galaxy. But they can sense the enormous gravitational power it has on the stars around it. Stars, which astronomers can see, orbit the black hole, at staggering speeds.

See for yourself. This video includes 16 years of observations from the European Southern Observatory. This isn’t an animation — it’s real images of stars sped up by a factor of 32 million. Watch them dance around a mysterious blank center.

A video of real images of stars sped up by a factor of 32 million.
A video of real images of stars sped up by a factor of 32 million.
ESO/MPE

And here’s a cleaner, illustrated version of similar observations, from the Keck Observatory in Hawaii.

[embedded content]

On Tuesday, Andrea Ghez, an astronomer at UCLA, and Reinhard Genzel, of the Max Planck Institute for Extraterrestrial Physics in Germany and UC Berkeley, shared half of the Nobel Prize in Physics for leading teams who made these extraordinary observations captured over three decades. (Ghez made them at the Keck Observatory, and Genzel led the European effort.) Ghez is now the fourth woman to have won the Nobel Prize in Physics.

“Stretching the limits of technology, [Ghez and Genzel] refined new techniques to compensate for distortions caused by the Earth’s atmosphere, building unique instruments and committing themselves to long-term research,” the Nobel Committee writes. “Their pioneering work has given us the most convincing evidence yet of a supermassive black hole at the centre of the Milky Way.”

Ghez and Genzel share this year’s prize with Roger Penrose, an emeritus professor at Oxford, who theorized that the existence of black holes is compatible with Einstein’s theory of gravity.

“Einstein did not himself believe that black holes really exist,” the Nobel Committee writes. “In January 1965, ten years after Einstein’s death, Roger Penrose proved that black holes really can form and described them in detail; at their heart, black holes hide a singularity in which all the known laws of nature cease. His groundbreaking article is still regarded as the most important contribution to the general theory of relativity since Einstein.”

Ghez and Genzel also proved in their work how Einstein’s theory of gravity is fundamentally correct.

Star S2, which is marked in the video above with a yellow line, is around 15 times as massive as our sun. But it’s nothing compared with the black hole, which is estimated to be some 4 million times more massive than our sun. The gravity it produces whips S2’s orbit to around 11 million miles per hour, which is about 200 times the speed the Earth orbits around the sun. S2 completes one orbit in around 16 Earth years.

Recently, both Genzel’s and Ghez’s teams witnessed S2 passing by Sagittarius A* at a speed greater than 15.5 million miles per hour. That’s more than 4,300 miles every second, or nearly 3 percent of the speed of light. S2 completes its orbit around the black hole in just 16 years, which allows these teams of astronomers to precisely compare the predictions of Einstein’s gravitational theory of something orbiting such a massive black hole with actual observations, proving the theory is watertight.

All the work awarded with the Nobel Prize Tuesday laid the groundwork for scientists to peer even deeper and closer at the black holes that live at the center of galaxies. In 2019, a worldwide effort called the Event Horizon Telescope published the first ever, up-close image of a black hole (the center of the Messier 87 galaxy). In the coming years, they may also resolve an image of the mysterious, powerful Sagittarius A* at the center of our own galaxy. And finally, we’ll see the source of all this gravitational power.


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Sports

In Pictures: Khabib Nurmagomedov, the undefeated MMA champion

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MMA world lightweight champion Khabib Nurmagomedov announced his shock retirement from the sport on Saturday after revealing he promised his mother his clash with Justin Gaethje would be his last fight.

The Russian, who won by a second-round technical knockout, was fighting for the first time since the death of his father Abdulmanap, who was also his coach, in July.

“I’m the UFC undisputed, undefeated champion with a 13-0 record (in UFC), and 29-0 in all of my pro MMA career,” he said after his win in Abu Dhabi.

“Today I want to say this is my last fight. No way am I coming here without my father.

“When UFC comes to me about Justin I spoke with my mother for three days. She didn’t want me to fight without father and I said this is my last fight – and I have given her my word.

“Thank you, coach, thank you, guys. Today is my last fight in the UFC.”

Abdulmanap Nurmagomedov, 57, passed away after COVID-19 related complications in the summer.

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Seychelles opposition candidate wins presidential election

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Ramkalawan, running for the presidency for the sixth time, won 54.9 percent of valid votes cast, poll body says.

Seychelles opposition candidate Wavel Ramkalawan has won the archipelago’s presidential election with 54.9 percent of valid votes cast, upsetting incumbent President Danny Faure.

“I declare… Ramkalawan as the elected candidate,” the electoral commission chairman Danny Lucas said on Sunday.

Voters on the main islands of Seychelles cast their ballot on Saturday in presidential and parliamentary elections spanning three days.

More than 74,000 registered to take part in the polls.

The opposition, narrowly defeated in a presidential election in 2015 and buoyed by a landmark victory in a parliamentary poll a year later, won its first presidential poll in the 40 years since Seychelles gained independence from Britain.

Ramkalawan, an Anglican priest and leader of the Seychelles Democratic Alliance, was running for the presidency for the sixth time. He lost the 2015 poll by 193 votes to James Michel in an unprecedented second round of voting.

The campaign took place mainly over social media, with rallies banned due to the coronavirus.

Seychelles has recorded only 149 cases, mostly imported, but the pandemic has been a burning campaign issue as restrictions on global travel bottom out the tourism industry – a major earner for Seychelles and employer for many of its 98,000 people.

Visitor numbers have collapsed since March in the archipelago nation of 115 islands, normally a popular destination for honeymooners and paradise-seekers drawn by its fine sandy beaches and turquoise waters.

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Thousands of seals found dead at breeding colony in Namibia

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Cause of mass die-off unknown but scientists suspect pollutants, bacterial infection, or malnutrition.

An estimated 7,000 Cape fur seals have been discovered dead at a breeding colony in central Namibia.

Conservationist Naude Dreyer of the charity Ocean Conservation Namibia (OCN) began noticing dead seals on the sandy beaches of Pelican Point colony – a tourist destination known for its colony of seals and schools of dolphins – near Walvis Bay city in September.

In the first two weeks of October, he found large numbers of seal foetuses at the colony.

Tess Gridley from the Namibian Dolphin Project estimated that between 5,000 and 7,000 female seals had miscarried young with more still being found.

Last week, there was a spike in the number of dead adult females, Dreyer said.

“What we have been observing is less freshly dead seal pups and a lot of dead female adults,” he said.

Fur seals normally give birth between mid-November and mid-December.

The cause of the mass die-off is yet to be established but scientists suspect anything from pollutants or bacterial infection to malnutrition.

Some of the dead females found were “thin-looking, emaciated, with very little fat reserves”, said Gridley.

In 1994, some 10,000 seals died and 15,000 foetuses were aborted in a mass die-off that was linked to starvation suspected to have resulted from a shortage of fish as well as from a bacterial infection at another breeding colony, the Cape Cross, some 116km (72 miles) north of the central tourist town Swakopmund.

Annely Haiphene, executive director in the Ministry of Fisheries and Marine Resources,  told AFP news agency she suspected the seals died from “lack of food” but will wait for the outcome of the tests.

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